clone disk: assert that drive name is the same for drive-mirror on single VM

because when the VM ID of target and source are the same,
qemu_drive_mirror_monitor() switches the QEMU device node over to the
new backing image. The planned import-from functionality makes it
possible to run into this, although for an a bit unusual use case.

Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>

diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index 6c80c0c24ecf0b8b3cbefc800b2c08b158a17b97..bc66246bfde5528cb515d0dc6dcf46fbe0cfedf3 100644 (file)
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -7585,11 +7585,17 @@ sub clone_disk {
     my ($newvmid, $dst_drivename, $efisize) = $dest->@{qw(vmid drivename efisize)};
     my ($storage, $format) = $dest->@{qw(storage format)};
 
+    my $use_drive_mirror = $full && $running && $src_drivename && !$snapname;
+
     if ($src_drivename && $dst_drivename && $src_drivename ne $dst_drivename) {
        die "cloning from/to EFI disk requires EFI disk\n"
            if $src_drivename eq 'efidisk0' || $dst_drivename eq 'efidisk0';
        die "cloning from/to TPM state requires TPM state\n"
            if $src_drivename eq 'tpmstate0' || $dst_drivename eq 'tpmstate0';
+
+       # This would lead to two device nodes in QEMU pointing to the same backing image!
+       die "cannot change drive name when cloning disk from/to the same VM\n"
+           if $use_drive_mirror && $vmid == $newvmid;
     }
 
     my $newvolid;
@@ -7644,7 +7650,12 @@ sub clone_disk {
        }
 
        my $sparseinit = PVE::Storage::volume_has_feature($storecfg, 'sparseinit', $newvolid);
-       if (!$running || !$src_drivename || $snapname) {
+       if ($use_drive_mirror) {
+           die "cannot move TPM state while VM is running\n" if $src_drivename eq 'tpmstate0';
+
+           qemu_drive_mirror($vmid, $src_drivename, $newvolid, $newvmid, $sparseinit, $jobs,
+               $completion, $qga, $bwlimit);
+       } else {
            # TODO: handle bwlimits
            if ($dst_drivename eq 'efidisk0') {
                # the relevant data on the efidisk may be smaller than the source
@@ -7661,11 +7672,6 @@ sub clone_disk {
            } else {
                qemu_img_convert($drive->{file}, $newvolid, $size, $snapname, $sparseinit);
            }
-       } else {
-           die "cannot move TPM state while VM is running\n" if $src_drivename eq 'tpmstate0';
-
-           qemu_drive_mirror($vmid, $src_drivename, $newvolid, $newvmid, $sparseinit, $jobs,
-               $completion, $qga, $bwlimit);
        }
     }